In some wireless communication protocols, for example, in Half Duplex Frequency Division Duplex (HD-FDD), the communication devices cannot transmit and receive at the same time. In such systems, the base station (BS) must ensure that the uplink (DL) and downlink (UL) traffic for these devices are not scheduled simultaneously. In addition, adequate time should be reserved to allow the HD communication devices to switch between transmission and reception modes. For HD-FDD systems, for example, a group-based frame structure is a well-known structure that simplifies traffic scheduling. In group-based frame structures, users are divided into multiple groups such that the DL traffic for one group does not overlap with the UL traffic for the same group. Based on this general concept, it is desirable to provide an efficient frame structure to enable various grouping strategies.
The various aspects, features and advantages of the invention will become more fully apparent to those having ordinary skill in the art upon a careful consideration of the following Detailed Description thereof with the accompanying drawings described below. The drawings may have been simplified for clarity and are not necessarily drawn to scale.